Low noise frequency stabilized laser for space-based gravitational wave detection

Under laboratory conditions (temperature approximately 22 degrees Celsius and humidity approximately 40%), a frequency comparison was conducted between the 1064nm test laser and the 1550nm reference laser using an optical frequency comb (Menlo System, Smart Comb). Simultaneously send the obtained beat frequency signal and the 10MHz signal of the active hydrogen clock (T4Science, iMaser3000) to the phase noise analyzer (Symmetricom, 5125A) for analysis, and calculate the frequency noise of the laser to be tested; Use a frequency counter (Pendulum, CNT-91) to collect the frequency of the beat signal, and the collected data is processed by Stable32 to obtain the frequency stability of the laser to be tested. Through phase comparison testing, the 1064nm stable frequency laser system has a frequency noise level of better than 30Hz/Hz1/2 between 30mHz and 1Hz, meeting LISA's requirements for laser frequency noise in the frequency range of 1mHz to 1Hz; the fractional frequency instability is 1.2×10-14 at 1s averaging time and 3×10-13 at 1000s averaging time。